Hydraulic drilling method and automatic control therefor



Oct. 25, 1932. c, $LATER ET AL 1,884,297

HYDRAULIC DRILLING METHOD AND AUTOMATIC CONTROL THEREFOR Filed April 23.1928 4 Sheets-Sheet l Edwin Ken/z e170 CSdater BY JWZZW Oct. 25, 1932.c, 5 1,884,297

HYDRAULIC DRILLING METHOD AND AUTOMATIC CONTROL THEREFOR I Filed April23, 1928 4 Sheets-Sheet 2 IN V EN TORS Edwin OBezuwtt Ken/will 0501a ter4 Sheets-Sheet 3 WINVENTIORS Edwia 0.5mm 1 BY Kzluwtlz 6501012," I

F 'My -l K. ,c. SCLATER ETAL Filed April 25, 192s mum; I!

Oct-25,1932.

'HYDRAULIC DRILLING ls'raon AND- AUTOMATIC CONTROL THEREFOR /a a m Oct.25, 1932. K; c. SCLATER ETAL 1,334,297

HYDRAULIC DRILLING IETHOD AND AUTOIATIC CONTROL THEREFOR Filed April 25.1928 4 Sheets-Sheet 4 BY KeIuwt/z 6'. S'clater Patented Oct. 25, 1932UNITED STATES PATEN OFFICE KENNETH C. SCLATER AND EDWIN BENNETT, OFPONCA CITY, OKLAHOMA 'HYDRAULIC DRILLING METHOD AND AUTOMATIC CONTROLTHEREFOR Application filed April 23, 1928. Serial No. 272,236.

This invention relates to improvements in hydraulic drilling methods andautomatic control therefor, and refers more particularly to a rotarydrilling method in which the bit rotating system and the hoisting systemof. a

for cores; a drilling method and system of control which will regulatethe torqueor turning effort on the'drill stem at all times and. willprevent the serious and detrimental effects resulting where permissiblelimits are exceeded; and finally, will provide a mechanismand methodwhich has the benefits of an unlimited number of speeds without jar orshock to the mechanism,-and other advanwith present drilling methods.

Fig. 1 is a side elevational view of the mechanism, with partsbrokenaway.

Fig. 2 is a plan view of the mechanism shown in Fig. 1.

Fig. 3 is a sectional side elevational view -of a hydraulic pump andmotor adapted to be Used in connection with the present invention.

Fig. 4is a sectional view of the automatic control mechanism.

Fig. 5 is a sectional view of the manually operated control mechanism.

Referring to the drawings, at 1 is shown a Deisel engine which is theprime mover most conveniently shown, but may be replaced by a steamengine, motor, or other type of power source. This type of engine isparticularly adapted to drilling where operations are being carried onat a considerable distance from an electrical power source, and

where wildcatting operations necessitate the use of a relatively small,convenient and R0 efficient prime mover. This engine is direct-connectedto two hytages which will be obvious to one familiarwith wedging slips.

draulic, variable speed, reversible gears or pumps 2 and 3. These pumpsare positioned at the ends of the engine and give a balancing effectwhen the engine is in operation. These pumps or hydraulic gears arepreferably of the type manufactured by either the Waterbury Tool Companyof Waterbury, Connecticut, or the Oil Gear Company of Milwaukee,Wisconsin, although the invention contemplates the use of any type ofreversible, variable speed, hydraulic pump.

The pump 2 is connected by fluid lines 4 and 5 to secondary connections6 and 7 leading to the fluid motor 8 and through lines 9 and 10 to thefluid motor 11. Valves 12 and 13 are positioned at the junction of thepipes to regulate the direction 'of'flow of the liquid. These valves maybe connectedto act jointly or separately as desired. Normally the willbe connected so as to be manipulated ointly. 'The fluid motors 8 and 11are direct-connected to the axle or shaft 14 of the hoisting drum 15.

The hydraulic pump 3 is connected by pipes 16 and 17 to the fluid motor18, the 7 shaft 19 of this fluid motor having at its outer extremity abeveled gear 20. The shaft is supported by a bearing diagrammaticallyshown at 21. The beveled gear 20 meshes with a larger beveled gearaffixed to .the'ro- 30 tary table which is mounted on the floor -of thedrilling derrick. The rotary table 22 is centrally apertured by a squarehole 23 into which-fits what is termed in drilling practice the Kelleyor grief stem 24 along To the bottom of the v grief stem is attached thedrill pipe 25 at the lower end of which is a bit 26.

The drill pipe and drill bit are supported by the hoisting system whichconsists of a hook 27 engaging a swivel head bail or loop a on the topof the grief stem by sheave blocks 28 and lines 29 rove over the crownblock 30 of the derrick 31, a portion of which is shown in Fig. 1, therest of the derrick having been broken away in the interest ofsimplicity. The live end 29 of the supporting lines 29 is reeled uponthe drum 15 which may be rotated in either direction by the motors 8 and11, or separately by either motor to I00 raise the bit from the bottomof the hole or lower the bit to an operating position when drillingoperations are being carried on.

The control system consists of a hydraulic cylinder 32 positioned abovethe controlling is attached tothe top of t is rod also a' wire 35running over the pulley 36 and attached to a sheave 37 rotatably pivotedon any convenient standard, such as a leg of the derrick 31 or othersuitable upright. A second wire or line 38 runs over a pulley 39 on thecontrol mechanism of the pump 3 and also over a pulley 37. This type ofcontrol is but one form of possible controls for this type of mechanism,and while this type is shown in the drawings for the purpose ofdisclosing an operable control, other types are contemplate A manuallyoper- 1 ated handle 40 furnishes a means for manipulating andcontrolling the pumps when the automatic control is to be eliminatedwhen pulling or running the pipe in the well, under which conditions thedrilling mechanism is not usually operated. This disengaging deviceeliminates the automatic control which functions as follows: A pressurecontrol line 41 is connected to the discharge of the pump 3 and to thecylinder 32. When the pressure in the pump 3 tends to exceed apredetermined value depending on the torque exerted on the drill bit 26,which is fixed to prevent damage due to excess strain, the piston withinthe cylinder 32 will be lifted and will cause the shaft or rod 33 totravel upwards. This upward motion of the control shaft serves toactuate the pump 2 so that the motor 8 or 11, whichever is connected, orboth, will rotate and lift the drill pipe up, relieving the load ortorque on the drill stem. When the load has been relieved the pressurein the line 41 will drop and the control cylinder 32 will be lowered andwill cause the control shaft 33 to travel downward' to a neutralposition and the hoisting drum 15 will come to rest. If the torque' onthe drill bit 26 is below the amount it is desired to maintain when thecontrol shaft reaches the neutral position the pressure in the line 41will be low enough to cause the piston within the control cylinder 32 tolower the control shaft 33 beyond the neutral position and the hoistingdrum will start rotating in the opposite direction to lower the bit to apoint where the desired torqueis maintained.

The amount of dead weight imposed upon the piston controlling the pump 2is asoertained to impose the pro er torque or pressure upon thedischarge 0 the pump 3, the

control being regulated by maintaining a relatively constant pressure inthe control line 41. When the equipment is in operation for drilling,the bit is rotated by means of the rotary table. Mud-laden fluid iscirculated down inside the drill pipe 25 and out through the watercourses in the bit This mud-laden fluid is used to carry awa cuttingsfrom the bit face, up and out o the hole. The mud fluid pipes areconnected to the drill pipe at its upper end by means of a flexible hoseand acked swivel head 48.

As the ri lling proceeds and the hole is deepened, more joints of drillpipe are added below the grief stem 24. During the process of drilling,the driller usually stands by the hoisting drum and feeds the bit.Heretofore this has been accomplished by paying out line from thehoisting drum at a desired rate, thus lowering the drill pipe andpermitting the bit to penetrate deeper into the rock structure. If toomuch line is paid out, excess weight will be placed upon the bit and thebit will wear rapidly, break,

or sometimes stick. If it sticks and there is suflicient ower on therotary table, the drill pipe may e completely twisted ofi', resulting ina shut-down of operations and the necessity of fishing out the partremaining in the hole.

bit the drill pipe will kink or become bent, thereby causing the hole tobe drilled ofi' plumb. In some instances in deep wells this deviationfrom the vertical may amount to as much as several hundred feet.

The results of a crooked well or one that has been drilled ofi lumb aredetrimental and cause reat difiicu ties in production after a well haseen completed. If a crooked hole is swabbed for production, the casingin the well is often worn throughby the wire line pulling the swab. Whena crooked well has to be pumped for production there is great danger ofthe pump rods cutting through the side of the tubing. Also on account ofadditional load, there is much greater wear and rod breakage in crookedwells, which cause shut-downs and resultant loss of production. There isalso great danger of twisting off the drill pipe where acrooked hole isbeing drilled, and additional power is necessary for drilling ascompared with the power necessary for a straight hole. The cores andcuttings from a crooked hole give erroneous geological informationregarding contour of subsurface structure.

A system of control that will regulate the torque or turning efiortonthe drill stem at all times will govern the pressure on the bit and willprevent the very serious detrimental effects resulting where permissibleloads are exceeded. The general practice in drilling is for a driller todetermine these conditions by feel or experience. When holes are drilledas deep as 8,000 feet, it can-readily be i If too much pressure isapplied on the seen that it is practically a physical impossibility forthe driller to control by feel and experiencealone, these conditions,with any degree of accuracy. Recently there has been developed a tensionindicator which is placed on the dead line. This indicator helps thedriller to control more closely his equipment, but at best there is anintermittent action and a proper control relies wholly upon humanvagaries.

Prior art There have been two automatic methods of controlling thetorque on the drill stem developed which are an improvement over thehand-controlled methods. One of these methods is operated electricallyand the other mechanicall Both are operated on a differential drive. Thetotal power'is divided between torque on the draw works or hoisting drumand torque on the rotary table. \Vhen the torque on the rotary tableexceeds a predetermined value, the differential gearing acts and causesthe hoisting drum to wind or unwind until desired conditions areestablished. Thus the bit is retrieved or allowed to travel ahead inaccordance with the torque imposed upon it. The obj ectionable featuresof these methods, however, are that they require considerably greaterequipment, the permissible range of speeds is' limited, clutches arenecessary for starting of the hoisting drum or rotary table, and suddenacceleration from rest to full speed is detrimental and imposesextremely high stresses in the shafting and various parts of theequipment;

Furthermore the electrical method de pends uopn the availability ofelectricalpower and requires operators skilled in the use of electricalequipment. Also these methods permit runnng the pipe into the hole onthe brake and over speeds are often encountered which cause failures ofequipment and possible loss of life.

The present method is a new and unique type of drive and control asapplied to oil Well drilling and earth boring operations by rotarymeans. It employs a rotary table and hoisting drum similar to equipmentin common practice. The principal difference from the methods discussedor methods in use is the manner in which the drilling and hoisting unitsare driven and the direct automatic method of control byhydraulic means.

The motors 8, 11 and 18 are connected to their pumps by pipes, one afeed line and the other a return-line. designed that the stroke of thefluid cylinders' contained-therein are variable and the direction offlow is reversible. A better understanding of how this variable strokehydraulic mechanism functions and how the direction of fluid flow isreversed will be had by reference to Figures 3, 4 and 5. Pumps 2 and 3operate at constant speed and in one The pump units are so direction ofrotation. They are driven by a suitable prime mover such as the engineshown at 1. When the control shaft 33 of the pump 2 is in a neutralposition the tilting box 49 which contains the socket ring 50 and inwhich the connecting rods 51 to the piston 52 are'socketed, isperpendicular to the control shaft 33. In this position there will benoreciprocation or movement of the pistons 52 in the cylinders and nofluid will be dis- I placed when the pump shaft 53 rotates. If thecontrol shaft 33 of the pump 2 is moved upward from a neutral position,the tilting box 49 will assume an angular position (other than withrespect to the pump shaft 53, and as the pump shaft 53 rotates, thepistons 52 Will'be given a reciprocating motion, causing the fluid to bepumped. The amount of lateral motion or reciprocation given to thepistons for each revolution of the pump shaft 53 depends upon theposition of the control shaft 33 and the angle which the tilting box 49makes with the shaft 53. It will beseen ward half of its rotary cycleeach piston will draw in fluid and during the downward half of, itsrotary cycle will expel fluid. The fluid is discharged through the valveplate 54,

thence through piping to the cylinders of the motor. This motor is alsoequipped with a valve plate 54 similar in construction to that of thepump. It will readily be seen from this brief description that thedirection of flow in the pipe 4 and 5 is governed by the position of thecontrol shaft 33 and depends upon the direction of theangle that thetilting box 49 makes with the horizontal shaft 53. The construction andoperation of the pump 3 are essentially the same as pump 2 except thatthe control shaft of the pump 3 is manually operated instead of beingautomatically operated. The construction of motors 8, 11 and 18 isessentially the same as motors 8, 11 and 18 is fixed, it will berealized that the speed of rotation ofthe motors will vary in accordancewith the displacement of the pumps 2 and 3 and will depend upon themovement and position of the control shafts of the pumps. It will alsobe seenthat the stem 25.

direction of rotation of the motors 8, 11 and 18 will be governed by theposition of the control shafts 33 and 42 of the pumps 2 and 3respectively, and whether the motors are operated ahead or in reversewill be regulated by the position of the control shafts with respect tothe neutral position of the pumps. From this it is evident that thecontrol shaft of the pumps can be set to cause'a large difference inspeed between the pump driving shaft and the motor shaft controlledthereby, the speed ratio being dependent upon the relative angles of thesocket rin of the pump and motor. Reversing of t e motor is accomplishedby shifting the pump control shaft across neutral from the oppositedirection. The pressure of the fluid circulated to the motors isgoverned by the resistance offered to turning the motor shaft and notupon the speed of the motor. The pressure in the fluid circuit will riseimmediately to meet the torque demands on the motor shaft up to thepressure limits of the machine. Therefore, this type of transm ssion hasa'wide range of speeds and can develop high torque at low speeds whichis very advantageous or starting conditions in drilling practice.

Referring now to the details of the two control mechanisms shown inFigures 4 and 5, and describing the association and control with thepumps 2 and 3, pipe 41 connects the high pressure fluid circuit of thevalve plate 54 of pump 3 with the cylinder 32 on the control shaft ofmotor 2. This pipe transmits iressure throu h the fluid contained in itetween the'hig pressure circuit in the amp 3 and the control cylinder 32in Fig. 4. When the pressure in the pump becomes too great on account ofthe work done by the motor 18 exerting too much torque, the pressureabove the limited valve which is determined by weights 34 on the pistonof the control cylinder 32, causes the control shaft 33 to move upward.

The motion of control shaft 33' causes fluid to be circulated betweenthe pump 2 and motors 8 and 11. These motors 8 and 11 then turn in adirection to wind up the cable on the drum 15. The winding up of thiscable lifts the bit 26 free from the formation which is being drilledand the torque in the shaft and motor 18 is decreased. The fluidpressure in the pump3, line 41 and cylinder 32 will then decrease andweights 34 will cause the shaft 33 of the cylinder 32 to traveldownward. This will cause the fluid in the pump 2 to be circulated sothat the motors 8 and 11 will rotate to allow the line on the drum tofeed out, thus allowing the bit to press into the formationwith'greater'force until the desired torque is maintained on the drilleither direction to raise or lower the drill n order to maintain thedesired torque there- Thus the drum T5 is rotated .in

on, and this torque is controlled by the pressure in the line 41. Therotation of the shaft 42 by means of the lever controls manually theangle of the tiltin box 49 in the pump 3 and thereby the spec anddirection of flow and amount of fluid being pumped.

The hydraulic pumping and motor mechanism are the universal hydraulic,variable speed ears manufactured by the W'aterbury Tool ompany, ofWaterbury, Connecticut, and no claim is made in the present invention tothis equipment, as hydraulic mechanism 0 any type may be used in placeof this equipment. The amount of fluid pumped may therefore be made tovary from zero 7 to a maximum, in either direction, the direction andvolume of fluid handled by the pumps depending upon the position of thestroke-controlling shafts designated as 33 on motor 2 and as 42 on motor3. These shafts project from the casingof the pump units and are made intwo types, one which operates the travel of the shaft by rotation andthe other by vertical translation and are shown in Figs. 4 and 5. Inthis method of hydraulic transmission we prefer to use the verticaltranslation method of control on the pum 2 and the rotativecontrol onthe control 5 aft 42 of the pump 3. It is understood, however, thateither method of control may be used.

The rotation of the motors depending for their power upon thesehydraulic pumps or gears is governed by the volume and pressure of oilpumped, and the direction of rotation of the motors 8, 11 and 18respectively, is controlled by the direction of flow through the pumps 2and 3 and their connecting lines to these motors.

The torque or turning efl'ort produced on the shafts of the motors isgoverned by the pressure of the fluid discharged from the pumps. Thistype of hydraulic pump orgear is primarily a constant torque unit, butwill develop torque in proportion to the pressure developed up to thelimits of the strength of the units. The allowable pressure on the unitis. governed by the setting of a pressure valve which permits theby'passin of the fluid from the pump discharge bac to the suction. Thespeed of the unit may be varied from zero to maximum while the torqueremains (practically constant.

The a vantage of using a separate hydraulic motor for the draw workshoist and the rotary table is: that each can be operated independentlyof the other. There is ab solutely no jar or shock in startin a loadwith this equipment, and it also a ords an infinite number of speedsattain-able at the willof the o rator'. The benefits of an unlimited numer of stepsin speed control without jar or shock will be ap reciated byone familiar with drilling met ods.

Since the torque delivered to the drill pipe is governed by the pressurein the pump under conditions: where greater torque is required. Theweight may be replaced by a spring which can be set at a variabletension or compression. Capstans or catheads may be operated by separatehydraulic motor units connected to the pumps 2 and 3 but not shown, suchunits eliminating the sprocket chain drive, overhead shaft in use atpresent.

While two motors have been shown connected .to the draw works drum toequalize the torque, one motor may be satisfactorily employed. Pipes 43and 44 communicate between the lines 4 and 16, and '5 and 17 re''spectively. Valves 45 and 46 are mterposed in the junctions of the lines43 and 16,- and 44 and 17. These valves arefor thepurpose of cutting ofithe motor driving the rotary table and throwing the pump in parallelwith the pump 2 connected to the draw works hoisting system. The valves12 and 13, as

suggested, will normally work in conjunction and will operatesimultaneously by a control from the derrick floor. They are so arrangedthat either one or I the draw works drum can be'cut oil of the circuit.When drilling is progressing it is only necessary to use one motor onthe draw works drum, and at such times the other ma be cut off. Thismakes the one motor which is used for retrieving or feeding out the linesupporting the drill pipe more sensitive to its action.

When it is necessary. to do heavy pulling, both motors are thrown on thesystem and a greater torque can be exerted. At' this time the control ofthe rotary table motor is changed so that both of the pumps-2 and 3 canbe operated on the circuit of the. mo-

tors 8 and -11, the motor .18 being cut out by the valves 45 and 46.

It will also be appreciated that with the arrangement shown, both pumpscan be applied to the rotary table should increased both motors on workssystem the'indicating gauge would be a fixed and sensitive mechanism,registering at all times the weight on the bit. Such an indicator isdiagrammatically shown at 47 We claim as our invention: 1. A rotarydrill mechanism comprising in combination a prime mover, a firsthydraulic pressure generator, a second hydraulic pressure generator, ahydraulic motor actuated by said first hydraulic pressure generator, a I

second hydraulic motor operated by said second pressure generator, andmeans responsive to variations of pressure in the first hydraulic systemfor controlling the pressure in said second pressure system.

2. A rotary drill mechanism comprising in combination a prime mover, afirst hydraulic pressure generator, a second hydraulic pressuregenerator, a hydraulic motor actuated by said first hydraulic'pressuregenerator, a second'hydraul'rc motor operated by said second pressuregenerator, and automatic means responsive to variations of pressure inthe hydraulic system for controlling the pressure in said secondpressure system.

:33. A rotary drlll mechanlsm comprls ng in "combination a prime mover,a first hydraulic pressure generator, a second hydraulic pressureenerator, a hydraulic motor actuated by said first hydraulic pressuregenerator, a

second hydraulic motor operated by said second pressure generator,automatic means responsive to variations of pressure in the firsthydraulic system for controlling the pressure insaid second pressuresystem, and means for manually operating said automatic means.

. KENNETH C. SCLATER.

EDWIN O. BENNETT.

speed-be necessary. A pressure gauge may be I inserted in the circuit ofthe draw works system and this will be indicative at all times of theweight at the bottom of the bit. The-registration of pressure on thisgauge would correspond to the registration of weight indicators now inuse on the dead lines in present day practice. The indicator on the deadthe indicatormust be removed. By use of the pressure "gauge in thehydraulic draw

